Input devices including proximity sensor devices (also commonly called touchpads or touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which the proximity sensor device determines the presence, location and/or motion of one or more input objects. In one example, the sensing region includes sensor electrodes used to measure changes in capacitance resulting from an input object (e.g., a finger or stylus) interacting with the sensing region. In addition, the input device may include a fingerprint sensor that uses optical sensing to detect ridges and valleys in a finger. However, optical sensing can require significant amounts of power when doing some functions such as detecting the presence of a finger when the input device is in a low-power mode.